The present disclosure describes systems and techniques relating to wireless charging of devices, for example, mobile devices such as mobile phones, smartphones, multimedia phones, portable media players, Global Positioning System (GPS) units, portable gaming systems, tablets, palm tops, and wearable devices.
A mobile device is often built from multiple devices, which can include a radio chip coupled with an antenna, a general purpose processor, and inertial and/or MEMS (Micro-Electromechanical Systems) sensors. In addition, some mobile devices include wireless charge receiving circuitry that enables charging of the battery in the device without needing to plug the device into the source of electricity with a wire or cable. For example, some smartphones and wearables (e.g., smart watches, personal fitness devices, and health monitor devices) include wireless charge receiving circuitry that allows the mobile device to be simply dropped onto a charging plate or table to recharge its battery.